Can Cats Drink Cow's Milk?

What would you use to lure a lost kitty out of a tight hiding spot? Cat food or perhaps a saucer of milk? Many believe the latter is a healthy feline treat, thanks in large part to nursery rhymes, cartoons and movies. But the surprising truth is that milk can cause serious problems for cats, so it's best avoided once they're full grown. Read on to find out why this typically healthful drink should be considered a no-no for felines.

Lactose Intolerance in Cats

Like humans, some cats can be lactose intolerant, meaning they don't have the enzyme (lactase) necessary to digest the milk sugar (lactose) found in milk. (It doesn't necessarily mean they don't enjoy drinking the milk.) Other kitties don't have a problem at all.

How can you tell if your cat falls in this category? Give a small amount of milk (think a tablespoon, tops) and be patient. A lactose-intolerant cat will usually show symptoms -- most commonly diarrhea and vomiting -- within eight to 12 hours of consumption. You may also see signs of dehydration, like increased water consumption, or an allergic reaction, such as excessive scratching or watery eyes. If you don't see any symptoms within a day, your cat likely produces an adequate amount of lactase.

Other dairy products, particularly cheese and yogurt, contain reduced amounts of lactose and are often easier on a cat's stomach, including those who may be lactose intolerant. Why? The lactose in these products is often diluted with added fats and water. Cultured dairy products include microorganisms that have partially broken down the lactase.

But Wait, Don't Kittens Drink Milk?

You're not crazy; kittens DO drink milk. Like all mammals, kittens nurse, drinking their mother's milk for nourishment. It's not a problem at this age because at birth, kittens possess lactase, the enzyme needed to process lactose, the sugar found in milk. But as cats age, their bodies create less and less of this enzyme, making the digestion of milk difficult to impossible.

The weaning process typically begins when kittens are about four weeks old and is usually completed when they're between eight and 12 weeks of age. Once kittens are completely weaned from their mothers and eating solid food, their bodies begin producing reduced amounts of lactose, if any at all.

Avoid Cow's Milk for Kittens

Are you taking on the role of "mother" for an abandoned kitten? Don't fill the bottle with your standard cow's milk. Though a kitten has the lactase needed to break down the milk, it doesn't have enough to handle the larger amount of lactose found in cow's milk. The proportion of whey to casein also poses a problem for kittens. The answer? Head to a pet store for a milk replacer created specifically for kittens. This usually consists of cow's milk that has been modified to be closer to the nutritional composition of cat's milk.

About the Author Tara Hall is an animal-loving writer and editor based in Austin, Texas. Her portfolio runs the gamut from small business marketing content to travel writing, fashion editorial and national music coverage.